In fluid flow transfer apparatus, such as hemodialyzers or artificial kidneys, it is necessary, at times, to expel air initially present in fluid circuits in the apparatus, such air expulsion being referred to as degassing. This need is acute when fluid travels downward through the apparatus in its normal mode of operation, for then initially entrapped air rises against the direction of fluid flow so that escape of the air is retarded.
The known method for degassing downwardly flowing fluid circuits is to turn the apparatus upside down until the initially entrapped air in the circuit has exited by going up with the now upwardly flowing fluid. This can be done by simply taking the apparatus out of its mount and manually rotating it, but this carries the risk of dropping the device, a serious matter when the apparatus is a hemodialyzer. Thus, it would be desirable to have a mount for the apparatus that permits rotation of the apparatus easily, reliably, and quickly into an upside down degassing position and locking therein and reliable return to a normal vertical operating position and locking therein, thus making removal of the apparatus for rotation unnecessary.
Rotatable mounts are known, but the need remains for a mount that securely holds the fluid flow apparatus in each desired position, that does not require careful adjustment to change position, and that facilitates insertion and removal of the apparatus from the mount.
A mount manufactured by Cordis Dow Corporation for a cylindrical hemodialyzer comprises a semicircular clamp into which the hemodialyzer is snapped and a generally C-shaped clamp which fits around an upright mounting pole and to which the semicircular clamp is rotatably connected back-to-back. A detent comprising a shaft extending horizontally from the semicircular clamp and having recesses circumferentially spaced apart at 30.degree. to cooperate with a spring-biased ball on the C-clamp permits holding the hemodialyzer in rotational positions 30.degree. apart. There are no means other than the detent, which is located at the site of rotation, for securing the hemodialyzer in a selected position.
Claff et al. U.S. Pat. No. 3,332,746 shows a mount having trunnions cooperating with a pair of shafts on opposite transverse surfaces of an oxygenator held in a vertical position and said to be tiltable in any direction. The mount has a lower horizontal bar, partially concealed in the drawing, which appears to support the oxygenator in a vertical position.
Claff et al. U.S. Pat. No. 3,060,934 shows a clamp for selectively locking an oxygenator in a desired tilted position.